This project will use data from the AHCPR's Healthcare Cost and Utilization Project (HCUP) to study how changes in health care markets have affected the quality of hospital care provided to vulnerable populations, especially minorities and the uninsured. Specifically, the project will use hospital populations, especially, especially minorities and the uninsured. Specifically, the project will use hospital discharge data for 13 states included in the State Inpatient Database (SID) to assess the effects of discharge data for 13 states include in the State Inpatient Database (SID) to assess the effects of competition in the managed care and hospital markets on: (1) the quality of care provided by hospitals focusing on potential differential effects for safety net and non safety net hospitals, (2) the degree of segmentation in hospital markets by patient insurance status (e.g, insured vs. uninsured). The project will use multivariate signal extraction models to construct the measures of hospital quality from form the discharge data. These models reduce the effect of noise in the data, incorporate information on multiple dimensions of quality, and permit identification of the dimensions that are most important empirically in carrying the quality signal. Therefore, in addition to its analytic goals, the project will make important methodological innovations in the use of discharge data to measure hospital quality.